Restrict the amp output - The "R33" resister is the key to regulating amperage.

For testing purposes, I soldered 2 wires of a 2s balance plug to the ends of the R33 resister. Then plugged a multi-turn 2K Pot (potentiometer) into the balance connector. Then I lowered the voltage to minimum and applied "load". Removing and measuring the pot's ohms at each 1/2 amp mark. (Pot must be removed to measure! "In circuit" it is laid parallel with R33.)

Yeah ... I'm gonna try pushing everything to the limits ... and then a little further!

(Will test to confirm) In Series

"In series" is when the negative of one power supply is run through the positive of another - combining their voltages.

Important!

When run in "series" the DC "negative" must be isolated from the 110AC negative ... on all but the primary unit!. Otherwise, the DC positive from the primary unit will "short" through the AC negative on the secondary unit.

The negatives are usually connected through the "ground".Not confirmed yet!!!It appears the S-350 series is ready for "in series" with no mods!Not confirmed yet!!!

I finally built my 33.3V 43.2Ah (9s20p) LiPo battery pack and needed a charger.I had planned to VET the S-350-48 and finally had a good reason.Filled in all mod info except increasing Amps.Though I did spec out the Amp regulation mods, my pack will be perfect with the oem Amp limit.

Fan ModThere is a fan mod posted, by shorting across some points ...I just cut the neg fan wire and ran it to the DC neg ... works fine!Charging 42Ah battery at 9.1A, I will want the fan to run constantly!

A little learning is a dangerous thing;Drink deep, or taste not the Pierian spring:There, shallow draughts intoxicate the brain,And drinking largely, sobers us again.

how did you go about figuring out all these mods, are you that smart? had schematics? I tried the same with pc PS had some success modding one to adjust voltage no Idea how to go about amps, thou that does not seem to be much of an issue , just curious, I look up to you and what you have done quite a bit. Always been a fan of the underdog, any daddys idiot can throw money or borow and default on payments at brand new plug and play stuff that may not even compare to your cheap setups, and that I think it's the beauty of what you are doing, my grandpa used to call it: " making a whip out of horseshit " and it snaps too.

2007blueprius wrote:how did you go about figuring out all these mods, are you that smart? had schematics? I tried the same with pc PS had some success modding one to adjust voltage no Idea how to go about amps, thou that does not seem to be much of an issue , just curious, I look up to you and what you have done quite a bit. Always been a fan of the underdog, any daddys idiot can throw money or borow and default on payments at brand new plug and play stuff that may not even compare to your cheap setups, and that I think it's the beauty of what you are doing, my grandpa used to call it: " making a whip out of horseshit " and it snaps too.

To a large extent, I expound upon the work of others.I hunt and investigate info on certain quality-useful-moddable, readily available items.Then, using basic methods, I investigate, test, mod, document ...I would rate myself as intelligent, blessed-cursed with an ingenuity which might be partly attributable to a degree of dyslexia, I see things differently than most people.I am very much a system rather than a component thinker.I amass a horrific amount of info then process it, almost subconsciously at times, when needed.

Most importantly, I try to provide clear and complete info-instructions.I will add current regulation mods as well as pictures.

Added S-350-48 to MeanWell Mods in Endless Sphere WikiI am concentrating on the "S Series".S-150-24 is complete, S-150-15 and S-150-5 are largely complete.S-350-48 is complete except for increasing Amp limit.And have begun S-350-24.Still have some S-320-xx to test

The S (Standard) Series is an older "simpler" version MeanWell that lends itself to simple mods.Later models added features and redundancies that make "simple" mods ... "difficult"?

Oh ... Fun?Bid low on a "New" MeanWell S-320-5 ... and won ...4.5-5.7V 50A! ... What could anyone ever use that for?

Run in series, it could properly current regulate an HP ESP120 (51.4V 57A) switching power supply as a 50A charger for a 48V large battery pack.

48.1V 13s x 4.2V = 54.6 (51.4V + 3.2V = 54.6V)

5.7V from the MeanWell is preferable. (5.7V x 50A = 285w)(13s x 3.7V = 48.1V and 48.1V is lower than 51.4V from the ESP120, and MeanWell would perform no regulation,54.6V - 5.7V = 48.9V which is still more than 48.1V but the .8V voltage differential ("pressure") should draw less than 50A! ... ?) I will have to implement voltage mods on the ESP120 but I have leads-clues on how to accomplish them.

If successful, and to what voltage modable, might work nicely with a 44.4V 12s x 4.2V = 50.4V?

OK Im going to jump on board. I have about 10 blown MW 350w 48v supplies. All have q1 and q2 blown. So here is my suggestion lets find a better transistor is it as simple as selecting a higher amp rated transistor? http://www.digikey.ca/product-detail/en ... -ND/810925 This one is 24 amps which is 9 amps more then the old one or 60% more so would someone be able to run 60% more amperage out of the unit? Even If I could mod it to run ~9-10 amps reliably it would be fine. What do you guys think?I have good luck up to 8 amps with a 48v supply but past that and they pop. Not to mention I order the cheep ones from ebay so I bet the 2sc3320 is cheep and might even be knock offs of something making them less reliable.

Arlo1 wrote:OK Im going to jump on board. I have about 10 blown MW 350w 48v supplies. All have q1 and q2 blown. So here is my suggestion lets find a better transistor is it as simple as selecting a higher amp rated transistor? http://www.digikey.ca/product-detail/en ... -ND/810925 This one is 24 amps which is 9 amps more then the old one or 60% more so would someone be able to run 60% more amperage out of the unit? Even If I could mod it to run ~9-10 amps reliably it would be fine. What do you guys think?I have good luck up to 8 amps with a 48v supply but past that and they pop. Not to mention I order the cheep ones from ebay so I bet the 2sc3320 is cheep and might even be knock offs of something making them less reliable.

i am not following this but the big high voltage switching transistors are on the front end so output voltage is not the issue imo. you may be limited in the current you can switch by the saturation of the transformer so a larger transistor may not help. just guessing.

Arlo1 wrote:OK Im going to jump on board. I have about 10 blown MW 350w 48v supplies. All have q1 and q2 blown. So here is my suggestion lets find a better transistor is it as simple as selecting a higher amp rated transistor? http://www.digikey.ca/product-detail/en ... -ND/810925 This one is 24 amps which is 9 amps more then the old one or 60% more so would someone be able to run 60% more amperage out of the unit? Even If I could mod it to run ~9-10 amps reliably it would be fine. What do you guys think?I have good luck up to 8 amps with a 48v supply but past that and they pop. Not to mention I order the cheep ones from ebay so I bet the 2sc3320 is cheep and might even be knock offs of something making them less reliable.

i am not following this but the big high voltage switching transistors are on the front end so output voltage is not the issue imo. you may be limited in the current you can switch by the saturation of the transformer so a larger transistor may not help. just guessing.

I was just thinking all my MWs that have died had those transistors pop and it was always over current so....

Ok so I got a 36v MW repaired. Had Q1 and Q2 blown and that was it. I tried 3 others so far and one makes noise from T1 and it changes if I push on the plastic. It makes 32v and does not adjust with the pot I belive its a 48v MW so something is not right maybe even T1 it self.

I changed out T1 and it will slowly climb to 52volts when the pot it cranked but if I put any load on it the voltage drops off to almost nothing.... Anyone have any ideas? This is a 350w MW most likely a knock off.

Warning! Check for voltage "isolation"! Build array without ground wire to 2nd or 3rd components.Do not let components touch each other.Check between units to confirm electrically isolated, casing to casing, (0V reading)Using a line with small fuse, test-connect ground to 2nd unit etc.